Answer:
P = 24.32 W
Explanation:
The question is, "Two resistors 5 Ω and 10 Ω are connected in parallel with a 9 V power supply. Calculate the output power of the power supply.".
The voltage of the power supply, V = 9 V
Resistor 1, R₁ = 5 Ω
R₂ = 10 Ω
The equivalent of parallel combination of resistors is given by :

The power of the output is given by :

So, the output power is equal to 24.32 W.
Answer: a) 7.71 m/s², b) - 6.67 m/s²
Explanation: first thing to note is that
1 mile = 1609.34
1 hour = 3600s
Hence, 100mph to m/s = (100 × 1609.34)/3600 = 44.71 m/s
Initial velocity (u) = 0, final velocity (v) = 44.71 m/s, t = 5.8s, a = acceleration =?
By using newton's laws of motion
v = u + at
44.71 = 0 + a(5.8)
44.71 = 5.8a
a = 44.71/5.8
a = 7.71 m/s²
Question b)
The car is completing a stop which implies that the car is coming to rest, and when a car is coming to rest, the final velocity (v) is zero.
Hence u = 34 m/s, v = 0, a =?, t = 5.1 s
v = u + at
0 = 34 + a(5.1)
a(5.1) = - 34
a = - 34/5.1
a = - 6.67 m/s².
The negative sign beside the acceleration shows that the body is decelerating
Answer: A. Resistance is directly related to length.
Explanation: Resistance is directly proportional to wire length. The longer the wire the greater resistance since there is more space for particles to collide. While resistance is inversely proportional with the cross- sectional area of a wire. The bigger the wire lower resistance.